U.S. patent number 11,341,362 [Application Number 16/266,738] was granted by the patent office on 2022-05-24 for methods and devices for updating fingerprint template.
This patent grant is currently assigned to BEIJING XIAOMI MOBILE SOFTWARE Co. Ltd.. The grantee listed for this patent is BEIJING XIAOMI MOBILE SOFTWARE CO., LTD.. Invention is credited to Zhongsheng Jiang.
United States Patent |
11,341,362 |
Jiang |
May 24, 2022 |
Methods and devices for updating fingerprint template
Abstract
A method of updating a fingerprint template in an electronic
device is provided. In an example, the method includes: a blank
image is acquired when a fingerprint sensor in the electronic
device scans a fingerprint sensor region and no finger is detected;
and it is determined whether the fingerprint template is to be
updated according to the blank image.
Inventors: |
Jiang; Zhongsheng (Beijing,
CN) |
Applicant: |
Name |
City |
State |
Country |
Type |
BEIJING XIAOMI MOBILE SOFTWARE CO., LTD. |
Beijing |
N/A |
CN |
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Assignee: |
BEIJING XIAOMI MOBILE SOFTWARE Co.
Ltd. (Beijing, CN)
|
Family
ID: |
1000006325035 |
Appl.
No.: |
16/266,738 |
Filed: |
February 4, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20190251393 A1 |
Aug 15, 2019 |
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Foreign Application Priority Data
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Feb 13, 2018 [CN] |
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201810150743.5 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G06V
40/1347 (20220101); G06K 9/6255 (20130101); G06V
40/1365 (20220101); G06V 40/50 (20220101) |
Current International
Class: |
G06K
9/62 (20220101); G06V 40/12 (20220101); G06V
40/50 (20220101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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105631443 |
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Jun 2016 |
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CN |
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105809133 |
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Jul 2016 |
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CN |
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106446775 |
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Feb 2017 |
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CN |
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106716446 |
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May 2017 |
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CN |
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107122761 |
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Sep 2017 |
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CN |
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Other References
Extended European Search Report Issued in EP Application No.
19156994.6, Jul. 1, 2019, (8p). cited by applicant .
Scheidat, Tobias et al., "Automatic Template Update Strategies for
Biometrics" Technical Report, May 31, 2007, (5p). cited by
applicant .
First Office Action issued in Chinese Application No.
201810150743.5 dated Feb. 2, 2021 with English translation, (23p).
cited by applicant .
First Office Action issued in European Application No. 19156994.6
dated Dec. 22, 2020, (5p). cited by applicant .
Second Office Action issued to Chinese Application No.
201810150743.5 dated Aug. 17, 2021 with English translation, (22p).
cited by applicant.
|
Primary Examiner: Flores; Roberto W
Attorney, Agent or Firm: Arch & Lake LLP
Claims
What is claimed is:
1. A method for updating a prestored fingerprint template,
comprising: acquiring, by an electronic device, a fingerprint image
of a finger; determining whether the fingerprint image matches the
prestored fingerprint template in a fingerprint template library;
in response to determining that the fingerprint image matches the
prestored fingerprint template, acquiring, by the electronic
device, a blank image when a fingerprint sensor in the electronic
device scans a fingerprint sensor region and no finger is detected,
wherein acquiring the blank image comprises: obtaining an output of
the fingerprint sensor in response to detecting no finger when the
fingerprint sensor scans the fingerprint sensor region, the output
including at least one of an output voltage or an output current,
and when the output of the fingerprint sensor is within a set range
indicating that the output of the fingerprint is stable and the
blank image is valid, receiving the blank image acquired by the
fingerprint sensor; after acquiring the fingerprint image matching
the prestored fingerprint template and the blank image,
determining, by the electronic device, an area of a first foreign
object region in the fingerprint image; determining, by the
electronic device, an area of a second foreign object region in the
blank image; in response to determining that the area of the first
foreign object region is greater than the area of the second
foreign object region, outputting, by the electronic device, a
prompt indicating that the finger has a residue and/or the finger
is hurt, and confirming, by the electronic device, not to update
the prestored fingerprint template; and in response to confirming
that the prestored fingerprint template is not updated, an
operation of updating the prestored fingerprint template is not
performed in a preset period, wherein the preset period starts from
when no updates of the prestored fingerprint template is
confirmed.
2. The method of claim 1, further comprising: in response to
determining that both of the area of the first foreign object
region and the area of the second foreign object region are less
than or equal to an area threshold, updating, by the electronic
device, the prestored fingerprint template with the fingerprint
image.
3. The method of claim 2, wherein updating, by the electronic
device, the prestored fingerprint template with the fingerprint
image comprises: removing, by the electronic device, the foreign
object region with an area less than or equal to the area threshold
in the fingerprint image based on an image processing algorithm to
obtain a processed fingerprint image; updating, by the electronic
device, the prestored_fingerprint template with the processed
fingerprint image; and deleting a previous fingerprint template in
the fingerprint template library.
4. The method of claim 1, further comprising: in response to
determining that the area of the first foreign object region or the
area of the second foreign object region is greater than the area
threshold, confirming, by the electronic device, not to update the
prestored fingerprint template.
5. An electronic device, comprises: a processor; and a storage
medium to store machine executable instructions; wherein when
executed, the machine executable instructions cause the processor
to: acquire a fingerprint image of a finger; determine whether the
fingerprint image matches a prestored fingerprint template in a
fingerprint template library; in response to determining that the
fingerprint image matches the prestored fingerprint template,
acquire a blank image when a fingerprint sensor in the electronic
device scans a fingerprint sensor region and no finger is detected,
wherein acquiring the blank image comprises: obtaining an output of
the fingerprint sensor in response to detecting no finger when the
fingerprint sensor scans the fingerprint sensor region, the output
including at least one of an output voltage or an output current,
and when the output of the fingerprint sensor is within a set range
indicating that the output of the fingerprint is stable and the
blank image is valid, receiving the blank image acquired by the
fingerprint sensor; after acquiring the fingerprint image matching
the prestored fingerprint template and the blank image, determine
an area of a first foreign object region in the fingerprint image;
determine an area of a second foreign object region in the blank
image; in response to determining that the area of the first
foreign object region is greater than the area of the second
foreign object region, output a prompt indicating that the finger
has a residue and/or the finger is hurt; in response to determining
that both of the area of the first foreign object region and the
area of the second foreign object region are less than or equal to
an area threshold, update the prestored fingerprint template with
the fingerprint image; in response to determining that the area of
the first foreign object region or the area of the second foreign
object region is greater than the area threshold, outputting a
prompt indicating that the finger has a residue and/or the finger
is hurt and confirm not to update the prestored fingerprint
template; and in response to confirming that the prestored
fingerprint template is not updated, an operation of updating the
prestored fingerprint template is not performed in a preset period,
wherein the preset period starts from when no updates of the
prestored fingerprint template is confirmed.
6. The device of claim 5, wherein when updating the prestored
fingerprint template with the fingerprint image, the processor is
further caused to: remove the foreign object region with an area
less than or equal to the area threshold in the fingerprint image
based on an image processing algorithm to obtain a processed
fingerprint image; update the prestored fingerprint template with
the processed fingerprint image; and delete a previous fingerprint
template in the fingerprint template library.
7. A non-transitory machine readable medium storing machine
executable instructions, the machine executable instructions cause
a processor to perform acts comprising: acquiring a fingerprint
image of a finger; determining whether the fingerprint image
matches a prestored fingerprint template in a fingerprint template
library; in response to determining that the fingerprint image
matches the prestored fingerprint template, acquiring a blank image
when a fingerprint sensor in an electronic device scans a
fingerprint sensor region and no finger is detected, wherein
acquiring the blank image comprises: obtaining an output of the
fingerprint sensor in response to detecting no finger when the
fingerprint sensor scans the fingerprint sensor region, the output
including at least one of an output voltage or an output current,
and when the output of the fingerprint sensor is within a set range
indicating that the output of the fingerprint is stable and the
blank image is valid, receiving the blank image acquired by the
fingerprint sensor; after acquiring the fingerprint image matching
the prestored fingerprint template and the blank image, determining
an area of a first foreign object region in the fingerprint image;
determining an area of a second foreign object region in the blank
image; in response to determining that the area of the first
foreign object region is greater than the area of the second
foreign object region, outputting a prompt indicating that the
finger has a residue and/or the finger is hurt; in response to
determining that both of the area of the first foreign object
region and the area of the second foreign object region are less
than or equal to an area threshold, updating the prestored
fingerprint template with the fingerprint image; in response to
determining that the area of the first foreign object region or the
area of the second foreign object region is greater than the area
threshold, outputting a prompt indicating that the finger has a
residue and/or the finger is hurt and confirming not to update the
prestored fingerprint template; and in response to confirming that
the prestored fingerprint template is not updated, an operation of
updating the prestored fingerprint template is not performed in a
preset period, wherein the preset period starts from when no
updates of the prestored fingerprint template is confirmed.
8. The non-transitory machine readable medium of claim 7, wherein
updating the prestored fingerprint template with fingerprint image
comprises: removing the foreign object region with an area less
than or equal to the area threshold in the fingerprint image based
on an image processing algorithm to obtain a processed fingerprint
image; updating the prestored fingerprint template with the
processed fingerprint image; and deleting a previous fingerprint
template in the fingerprint template library.
Description
CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to Chinese Patent Application No.
201810150743.5 and filed on Feb. 13, 2018, the entire content of
which is incorporated herein by reference.
TECHNICAL FIELD
The present disclosure relates to updating a fingerprint
template.
BACKGROUND
At present, a fingerprint sensor is configured in some electronic
devices. A user can normally use the electronic device after
placing a finger on the fingerprint sensor and passing the
fingerprint identification. The accuracy of fingerprint matching
may be relatively low due to user finger peeling, temperature
changes, moisture changes, or wounds.
To improve the accuracy of fingerprint matching, some fingerprint
identification algorithms may have template updating and template
learning capabilities. For example, when a fingerprint image
matches a fingerprint template, the fingerprint image is stored in
a fingerprint template library as a new fingerprint template, and
then when fingerprint information is subsequently acquired, the
fingerprint information is compared with the new fingerprint
template, thereby improving the accuracy of fingerprint
matching.
SUMMARY
Based on this, the present disclosure provides a method of updating
a fingerprint template, an electronic device and a non-transitory
machine readable medium.
In first aspect, a method of updating a fingerprint template is
provided, which includes: acquiring a blank image when a
fingerprint sensor in the electronic device scans a fingerprint
sensor region and no finger is detected; and determining whether
the fingerprint template is to be updated according to the blank
image.
In second aspect, an electronic device is provided, which includes:
a processor; and a storage medium to store machine executable
instructions; wherein when reading the machine executable
instructions, the processor is caused to: acquire a blank image
when a fingerprint sensor in the electronic device scans a
fingerprint sensor region and no finger is detected; and determine
whether the fingerprint template is to be updated according to the
blank image.
In third aspect, a non-transitory machine readable medium is
provided. The non-transitory machine readable medium stores machine
executable instructions. When reading the machine executable
instructions, a processor is caused to perform the method of the
first aspect.
It shall be appreciated that the above general descriptions and the
following detailed descriptions are merely illustrative and
explanatory and cannot limit the present disclosure.
BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings, which are incorporated in and constitute
a part of this specification, illustrate examples consistent with
the present disclosure and, together with the description, serve to
explain the principles of the disclosure.
FIG. 1 is a flow diagram illustrating a method of updating a
fingerprint template according to an example;
FIG. 2 is a flow diagram illustrating a method of updating a
fingerprint template according to another example;
FIG. 3 is a flow diagram illustrating a method of updating a
fingerprint template according to yet another example;
FIG. 4 is a flow diagram illustrating a method of updating a
fingerprint template according to yet another example;
FIG. 5 is a flow diagram illustrating a method of updating a
fingerprint template according to still another example;
FIG. 6 is a block diagram of an apparatus for updating a
fingerprint template according to one or more examples;
FIG. 7 is a block diagram of an apparatus for updating a
fingerprint template according to one or more examples;
FIG. 8 is a block diagram of an apparatus for updating a
fingerprint template according to one or more examples;
FIG. 9 is a block diagram of an apparatus for updating a
fingerprint template according to one or more examples;
FIG. 10 is a block diagram of an apparatus for updating a
fingerprint template according to one or more examples;
FIG. 11 is a block diagram of an apparatus for updating a
fingerprint template according to one or more examples; and
FIG. 12 is a block diagram of an electronic device according to an
example.
DETAILED DESCRIPTION
Illustrative examples will be described in detail here with the
examples thereof expressed in the drawings. Where the following
descriptions involve the drawings, like numerals in different
drawings refer to like or similar elements unless otherwise
indicated. The examples described in the following examples do not
represent all examples consistent with the present disclosure.
Rather, they are merely device examples consistent with some
aspects of the present disclosure as detailed in the appended
claims.
The terminology used in the present disclosure is for the purpose
of describing particular examples only and is not intended to limit
the present disclosure. As used in this disclosure and the appended
claims, the singular forms "a", "an", and "the" are intended to
include the plural forms as well, unless the context clearly
indicates otherwise. It should also be understood that the term
"and/or" as used herein refers to and includes any and all possible
combinations of one or more of the associated listed items.
It shall be understood that, although the terms "first," "second,"
"third," and the like may be used herein to describe various
information, the information should not be limited by these terms.
These terms are only used to distinguish one category of
information from another. For example, without departing from the
scope of the present disclosure, first information may be termed as
second information; and similarly, second information may also be
termed as first information. As used herein, the term "if" may be
understood to mean "when" or "upon" or "in response to" depending
on the context.
Under the condition that the fingerprint identification algorithm
has template learning and template updating capabilities, when a
fingerprint sensor has hardware damage or residues, in the
fingerprint matching process, a updated fingerprint template
eliminates influence regions (hereinafter also referred to as
foreign object regions), such as hardware damages or residues. When
the remaining part of the fingerprint image except the foreign
object region matches the updated fingerprint template, the
electronic device is automatically unlocked. In this case, the area
of the matched region is reduced. When the two fingerprints are
similar, the recognition error rate is increased, and the safety
performance of the electronic device is reduced.
Based on this, the present disclosure provides a method of updating
a fingerprint template. FIG. 1 is a flow diagram illustrating a
method of updating a fingerprint template according to an example.
The method may be configured in a fingerprint sensor or a
processor. For brief, the method is performed by a processor in
examples of the disclosure. Referring to FIG. 1, the method of
updating a fingerprint template includes steps 101-102.
At step 101, a blank image is acquired when the fingerprint sensor
in the electronic device scans a fingerprint sensor region and no
finger is detected.
In an example, the fingerprint sensor is configured in the
electronic device, such as a mobile terminal, and is configured to
scan the fingerprint sensor region according to a set cycle to
obtain the blank image of the fingerprint sensor region. The
fingerprint sensor then sends the blank image to the processor.
The blank image refers to an image of a fingerprint sensor region
acquired by the fingerprint sensor without being interfered by a
user. It can be understood that when the hardware of the
fingerprint sensor is damaged or there is a residue in the
fingerprint sensor region, the hardware damage or the residue
affects a capacitance distribution of the fingerprint sensor, and
thus the blank image includes a foreign object region. The foreign
object region included in the blank image corresponds to a hardware
damage or a residue. The foreign object region shows an approximate
shape and an approximate position of the hardware damage or the
residue.
In practical applications, the fingerprint sensor may be a
capacitive sensor. When a finger enters a sensing region of the
fingerprint sensor, the capacitance value of each capacitance dot
in the sensing region of the fingerprint sensor changes, and thus
an output voltage of the fingerprint sensor changes. In an example,
the processor may obtain the output voltage of the fingerprint
sensor. The output voltage of the fingerprint sensor may refer to
an average value of the voltage corresponding to each of the
capacitance dots). When the output voltage of the fingerprint
sensor exceeds a preset voltage range, the processor does not
receive the blank image corresponding to the output voltage. When
the output voltage of the fingerprint sensor is within the preset
voltage range, for example, 5-50 mV, it indicates that the output
voltage of the fingerprint sensor is stable and the acquired blank
image is valid, and at this case the processor receives the blank
image.
It will be appreciated that the processor may further obtain an
output current of the fingerprint sensor. When the finger enters
the sensing region of the fingerprint sensor, the capacitance value
of each capacitance dot in the sensing region of the fingerprint
sensor changes, and thus the current value in a loop formed by each
of the capacitance dots and the power supply is different. In an
example, the processor may obtain the output current of the
fingerprint sensor. When the output current of the fingerprint
sensor exceeds a preset current range, the processor does not
receive the blank image corresponding to the output current. When
the output current of the fingerprint sensor is within the preset
current range, for example, 5-100 uA, it indicates that the output
current of the fingerprint sensor is stable and the acquired blank
image is valid, and at this case the processor receives the blank
image.
In another example, the processor takes a blank image received
within a preset period (such as, several milliseconds, several tens
milliseconds) after fluctuation of the output (may be an output
voltage or an output current) of the fingerprint sensor is ended as
a final acquired blank image.
At step 102, it is determined whether the fingerprint template is
to be updated according to the blank image.
After acquiring the blank image, the processor of the mobile
terminal determines whether the blank image includes a foreign
object region with an area exceeding an area threshold to obtain a
determination result, and then determines whether the fingerprint
template is to be updated according to the determination result.
Determining whether the fingerprint template is to be updated
according to the determination result includes: when the blank
image includes a foreign object region with the area exceeding the
area threshold, confirming not to update the fingerprint
template.
In an example, when it is determined that the fingerprint template
is not updated, the processor may not perform the operation of
updating the fingerprint template in a preset period (for example,
several minutes, or several hours) started from the determination
time. That is, when detecting that the finger of the user is close
to or pressing the fingerprint sensor, the processor determines
whether an acquired fingerprint image matches the fingerprint
template and confirms not to update the fingerprint template. When
the fingerprint image matches the fingerprint template, the
processor unlocks the mobile terminal. When the fingerprint image
does not match the fingerprint template, the locked state of the
mobile terminal is maintained. Therefore, when the blank image is
abnormal, the frequency of determining whether the fingerprint
template is to be updated or not can be reduced and thus the
computing resource of the processor can be saved.
In an example, when it is determined that the fingerprint template
is not updated, the processor does not use first acquired
fingerprint image after the determined time to update the
fingerprint template. After the first fingerprint image is
acquired, the processor re-executes step 101. In this way, it can
be found out in time whether the user removes the foreign object,
and the efficiency of updating the fingerprint template can be
ensured.
Determining whether the fingerprint template is to be updated
according to the determination result may further include: when the
blank image includes a foreign object region with an area less than
or equal to the area threshold or no foreign object region, the
fingerprint template may be updated. In an example, the method of
updating a fingerprint template further includes: storing a
fingerprint image matched with the fingerprint template into a
fingerprint template library as a new fingerprint template.
In some cases, the number of fingerprint templates in the
fingerprint template library is preset, for example, 100. In the
early stage of using the mobile terminal, the number of fingerprint
templates configured in the mobile terminal and fingerprint
templates stored when the user registers is N, where N is an
integer equal to or less than 100. In this case, the subsequent
fingerprint image passing the fingerprint identification may be
directly stored in the fingerprint template library as the
fingerprint template. In this way, the number of the fingerprint
templates can be stably increased, and thus the fingerprint
template library can adapt to more fingerprint identification
scenes.
In another example, the method of updating a fingerprint template
further includes: removing the foreign object region with the area
less than or equal to the area threshold in the fingerprint image
based on an image processing algorithm to obtain a processed
fingerprint image; storing the processed fingerprint image into the
fingerprint template library; and deleting a previous fingerprint
template in the fingerprint template library.
In some cases, the fingerprint template algorithm continuously
updates the fingerprint template, such that the number of templates
in the fingerprint template library is maintained at 100. At this
case, an old fingerprint template in the fingerprint template
library is replaced with a current processed fingerprint image,
that is, when a new fingerprint template is added in the
fingerprint template library, an old fingerprint template is
removed from the fingerprint template library. In this way, the
fingerprint template library does not occupy too many storage
resources, and thus the updating speed and the matching accuracy of
the fingerprint template can be ensured.
The size of the area threshold can be reasonably set according to a
relationship between the area threshold and a similarity between
the fingerprint image and the fingerprint template. For example,
the ratio of the area threshold to the fingerprint sensor region
may be 10% to 20%, and at this case, the similarity between the
fingerprint image and the fingerprint template is 80% to 90%. Of
course, those skilled in the art may adjust the area threshold
according to a specific scene, and the area threshold is not
limited herein.
It can be seen that the fingerprint template is not updated when
the area of the foreign object region in the blank image exceeds
the area threshold. In this way, the accuracy of the fingerprint
template can be ensured, it is avoided that the fingerprint image
with the hardware damage or the residue is used as the fingerprint
template and that the fingerprint identification can be succeeded
as long as fingerprints around the foreign object region passes the
fingerprint matching, so that the accuracy of the fingerprint
identification is prevented from being reduced and the safety
performance of the electronic device is ensured.
FIG. 2 is a flow diagram illustrating a method of updating a
fingerprint template according to an example. Referring to FIG. 2,
the method of updating a fingerprint template includes steps
201-203.
At step 201, a blank image is acquired when a fingerprint sensor in
the electronic device scans a fingerprint sensor region and no
finger is detected.
Step 201 is the same as step 101 and detailed description may refer
to FIG. 1 and step 101, which are not repeated herein.
At step 202, a fingerprint image matched with a fingerprint
template is acquired.
It is noted that, in examples of the disclosure, the sequence of
step 201 and step 202 is not limited, for example, step 201 may
precede step 202, and step 201 may follow step 202.
At step 203, it is determined whether the fingerprint template is
to be updated according to the fingerprint image and the blank
image. For example, the electronic device may determine whether to
update the fingerprint template according to the fingerprint image,
the blank image, and other factors such as an area threshold.
FIG. 3 is a flow diagram illustrating a method of updating a
fingerprint template according to an example. Referring to FIG. 3,
the method of updating a fingerprint template is performed by a
processor in an electronic device and includes steps 301-307.
At step 301, a blank image in the fingerprint sensor region is
acquired.
At step 302, it is determined whether the blank image includes a
foreign object region with an area greater than an area threshold.
When yes, step 303 is executed; and when no, step 304 is
performed.
At step 303, it is determined that the fingerprint template is not
updated and go back to step 301.
At step 304, a fingerprint image matched with the fingerprint
template is acquired.
At step 305, the blank image and the fingerprint image are
compared.
At step 306, it is determined whether the fingerprint image
includes a foreign object region with an area greater than the area
threshold. When yes, go back to step 303; and when no, step 307 is
performed.
At step 307, the fingerprint template is updated.
In an example, the fingerprint template is updated when there is no
foreign object region in the blank image and no foreign object
region in the fingerprint image. In another example, the
fingerprint template is updated when there is no foreign object
region in the blank image and the fingerprint image includes a
foreign object region with an area less than or equal to the area
threshold. In yet another example, it is determined that the
fingerprint template is not updated when there is no foreign object
region in the blank image and the fingerprint image includes a
foreign object region with an area exceeding the area
threshold.
When there is no foreign object region in the blank image, it is
determined that the fingerprint sensor has no hardware damage and
that the fingerprint sensor region has no residue. At this case,
when the fingerprint image includes a foreign object region, the
processor may directly determine that the foreign object exists in
the finger of the user, and prompt the user in a setting way, such
as popping up a dialog box, a message and the like, so that the
user can remove the foreign object in the finger in time.
In some cases, the fingerprint template is updated when the blank
image includes a foreign object region with an area less than or
equal to the area threshold and the fingerprint image includes a
foreign object region with an area less than or equal to the area
threshold. In some cases, it is determined that the fingerprint
template is not updated when the blank image includes a foreign
object region with an area less than or equal to the area threshold
and the fingerprint image includes a foreign object region with an
area exceeding the area threshold.
When the blank image includes a foreign object region, and the
foreign object region in the blank image and the foreign object
region in the fingerprint image have substantially the same shape,
it may be determined that the hardware damage of the fingerprint
sensor or the residue on the fingerprint sensor affects the
fingerprint image. When the blank image includes a foreign object
region, and the area of the foreign object region in the
fingerprint image is larger than that of the foreign object region
in the blank image, it may be determined that there is a foreign
object in the finger of the user. At this case, the processor may
prompt a user in a setting way, such as popping up a dialog box, a
message and the like, so that the user can remove the foreign
object in the finger in time.
FIG. 4 is a flow diagram illustrating a method of updating a
fingerprint template according to an example. Referring to FIG. 4,
the method of updating a fingerprint template includes steps
401-406.
At step 401, a fingerprint image matched with the fingerprint
template is acquired.
In an example, when detecting that the finger of the user is close
or pressing the fingerprint sensor, the fingerprint sensor scans
the fingerprint sensor region to acquire a fingerprint image and
transmits the fingerprint image to the processor. Then the
processor determines whether the fingerprint image matches the
fingerprint template. When the fingerprint image does not matches
the fingerprint template, the fingerprint sensor continues to scan
the fingerprint sensor region. When the fingerprint image matches
the fingerprint template, the fingerprint sensor acquires a blank
image after the finger leaves the fingerprint sensor region and
sends the blank image to the processor.
At step 402, a blank image in the fingerprint sensor region is
acquired.
At step 403, the fingerprint image and the blank image are
compared.
At step 404, it is determined whether the blank image or the
fingerprint image includes a foreign object region with an area
exceeding the area threshold. When yes, step 405 is performed; and
when no, step 406 is performed.
At step 405, it is determined that the fingerprint template is not
updated and go back to step 402.
At step 406, the fingerprint template is updated.
The processor compares the blank image with the fingerprint image
and determines whether to update the fingerprint template according
to the comparison result. In an example, the fingerprint template
is updated when there is no foreign object region in the blank
image and no foreign object region in the fingerprint image. In
another example, the fingerprint template is updated when there is
no foreign object region in the blank image and the fingerprint
image includes a foreign object region with an area less than or
equal to the area threshold. In yet another example, it is
determined that the fingerprint template is not updated when there
is no foreign object region in the blank image and the fingerprint
image includes a foreign object region with an area exceeding the
area threshold. In yet another example, the fingerprint template is
updated when the blank image includes a foreign object region with
an area less than or equal to the area threshold and the
fingerprint image includes a foreign object region with an area
less than or equal to the area threshold. In yet another example,
it is determined that the fingerprint template is not updated when
the blank image includes a foreign object region with an area
exceeding the area threshold and the fingerprint image includes a
foreign object region with an area exceeding the area
threshold.
In this example, the user may be prompted about the comparison
result in a setting way, and the prompting way may refer to the
description about FIG. 3, which is not described in detail
herein.
In above examples, the blank image and the fingerprint image both
are considered. In a case that the blank image and the fingerprint
image both include no foreign object or that the blank image and
the fingerprint image both include a foreign object region with an
area less than or equal to the area threshold, the fingerprint
template is updated. In other cases, it is determined that the
fingerprint template is not updated. In this way, the accuracy of
the fingerprint template can be ensured, at some cases, such as a
relatively large area of the hardware damage of the fingerprint
sensor region, a relatively large residue in the fingerprint sensor
region, a relatively large area in which the finger of the user is
hurt or a relatively large residue in the finger of the user, it
can be avoided that the fingerprint template is updated and thus
the accuracy of the fingerprint identification is not reduced, so
that the safety performance of the electronic device is
ensured.
FIG. 5 is a flow diagram illustrating a method of updating a
fingerprint template according to an example. Referring to FIG. 5,
the method includes steps 501-505.
At step 501, a blank image is acquired when a fingerprint sensor in
the electronic device scans a fingerprint sensor region and no
finger is detected.
At step 501 may refer to FIGS. 1-4, which is not described
herein.
At step 502, a fingerprint image matched with a fingerprint
template is acquired.
Step 502 may refer to FIGS. 1-4, which is not described herein.
At step 503, it is determined whether the fingerprint template is
to be updated according to the fingerprint image and the blank
image.
Step 503 may refer to FIGS. 1-4, which is not described herein.
At step 504, the foreign object region with the area less than or
equal to the area threshold in the fingerprint image is removed
based on an image processing algorithm to obtain a processed
fingerprint image.
In some cases, the processor removes the foreign object region in
the fingerprint image based on the image processing algorithm when
the blank image includes a foreign object region with an area less
than the area threshold and the fingerprint image includes a
foreign object region with an area less than the area
threshold.
The image processing algorithm may be an image processing algorithm
well known to those skilled in the art, and the image processing
algorithm is used to remove the foreign object region from the
corresponding fingerprint image. Of course, an image processing
algorithm with a fingerprint repairing function can be used to
adjust the fingerprints according to the trend of the fingerprints
around the foreign object region, so that a processed fingerprint
image is obtained.
At step 505, the fingerprint template is updated with the processed
fingerprint image.
The fingerprint template is updated with the processed fingerprint
image. The processed fingerprint image without the foreign object
region is used as the fingerprint template, so that the accuracy of
the fingerprint template can be improved, the accuracy of the
fingerprint identification can be improved, and the safety
performance of the electronic device is ensured.
An apparatus for updating a fingerprint template is provided by
examples of the present disclosure. FIG. 6 is a block diagram of an
apparatus for updating a fingerprint template according to an
example. Referring to FIG. 6, the apparatus 600 for updating a
fingerprint template includes:
a blank image acquiring module 601, configured to acquire a blank
image when a fingerprint sensor in the electronic device scans a
fingerprint sensor region and no finger is detected;
a fingerprint template updating module 602, configured to determine
whether the fingerprint template is to be updated according to the
blank image.
In an example, FIG. 7 is a block diagram of an apparatus for
updating a fingerprint template according to an example. On the
basis of the apparatus for updating a fingerprint template shown in
FIG. 6, referring to FIG. 7, the blank image acquiring module 601
includes:
an output acquiring unit 701, configured to acquire an output of
the fingerprint sensor; and
a blank image receiving unit 702, configured to receive a blank
image acquired by the fingerprint sensor when the output of the
fingerprint sensor is within a set range.
In an example, FIG. 8 is a block diagram of an apparatus for
updating a fingerprint template according to an example. On the
basis of the apparatus for updating the fingerprint template shown
in FIG. 6, referring to FIG. 8, the fingerprint template updating
module 602 includes:
a determining unit 801, configured to determine whether the blank
image includes a foreign object region with an area greater than an
area threshold; and
a first fingerprint template updating unit 802, configured to
confirm not to update the fingerprint template when the blank image
includes a foreign object region with an area greater than the area
threshold, and update the fingerprint template when the blank image
does not include any foreign object region with an area greater
than the area threshold.
In an example, FIG. 9 is a block diagram of an apparatus for
updating a fingerprint template according to an example. On the
basis of the apparatus for updating a fingerprint template shown in
FIG. 6, referring to FIG. 9, the apparatus further includes:
a fingerprint image acquiring module 901, configured to obtain a
fingerprint image matched with the fingerprint template.
The fingerprint template updating module 602 is further configured
to determine whether the fingerprint template is to be updated
according to the fingerprint image and the blank image when the
fingerprint image matches the fingerprint template, determining, by
the electronic device.
In an example, FIG. 10 is a block diagram of an apparatus for
updating a fingerprint template according to an example. On the
basis of the apparatus for updating the fingerprint template shown
in FIG. 9, referring to FIG. 10, the fingerprint template updating
module 602 further includes:
a comparing unit 1001, configured to compare the fingerprint image
with the blank image and send a comparison result to a second
fingerprint template updating unit 1002; and
the second fingerprint template updating unit 1002, configured to
update the fingerprint template when the fingerprint image includes
no foreign object region or a foreign object region with an area
less than or equal to the area threshold.
In an example, the second fingerprint template updating unit 1002
is further configured to update the fingerprint template when the
fingerprint image a foreign object region with an area less than or
equal to the area threshold and the blank image a foreign object
region with an area less than or equal to the area threshold.
In an example, FIG. 11 is a block diagram of an apparatus for
updating a fingerprint template according to an example. On the
basis of the apparatus for updating the fingerprint template shown
in FIG. 10, referring to FIG. 11, the fingerprint template updating
module 602 further includes:
a foreign object region removing unit 1101, configured to remove
the foreign object region with the area less than or equal to the
area threshold in the fingerprint image based on an image
processing algorithm to obtain a processed fingerprint image.
The second fingerprint template updating unit 1002 is further
configured to update the fingerprint template with the processed
fingerprint image.
In an example, the second fingerprint template updating unit 1002
is further configured to confirm not to update the fingerprint
template when the fingerprint template includes a foreign object
region with the area greater than the area threshold.
It is noted that the apparatus for updating a fingerprint template
provided by examples of the present disclosure substantially
corresponds to the method of updating a fingerprint template, and
since the steps of the method of updating a fingerprint template
have been described in detail in the above examples, the apparatus
examples may refer to the method examples. In addition, with the
change of the application scene, the method of updating the
fingerprint template may also make corresponding adjustment, and
the apparatus for updating the fingerprint template may also adopt
different functional components to re-adjust, and further detail is
omitted.
As shown in FIG. 12, it is a block diagram of an electronic device
according to an example. The electronic device 1200 may be a mobile
phone, a computer, a digital broadcasting terminal, a message
transceiver, a game console, a tablet device, a medical device, a
fitness facility, and a personal digital assistant.
With reference to FIG. 12, the electronic device 1200 may include
one or more of: a processing component 1202, a memory 1204, a power
supply component 1206, a multimedia component 1208, an audio
component 1210, an Input/Output (I/O) interface 1212, a sensor
component 1214, and a communication component 1216.
The processing component 1202 generally controls the overall
operations of the electronic device 1200, such as operations
associated with display, calling, data communication, camera
operation and recording operation. The processing component 1202
may include one or more processors 1220 for executing instructions
to complete all or part of steps of the above-described method.
Besides, the processing component 1202 may include one or more
modules to facilitate interactions between the processing component
1202 and other components. For example, the processing component
1202 may include a multimedia module to facilitate the interaction
between the multimedia component 1208 and the processing component
1202. In an example, when reading the machine executable
instructions, the processor 1220 is caused to perform the above
method.
The memory 1204 is configured to store different types of data to
support the operations of the electronic device 1200. Examples of
such data include instructions of any application program or method
operable on the electronic device 1200, contact data, telephone
directory data, messages, pictures, videos, and the like. The
memory 1204 may be implemented by any type of volatile or
non-volatile storage device or a combination thereof, such as a
Static Random Access Memory (SRAM), an Electrically Erasable
Programmable Read-Only Memory (EEPROM), an Electrically
Programmable Read-Only-Memory (EPROM), a Programmable
Read-Only-Memory (PROM), a Read-Only Memory (ROM), a magnetic
memory, a flash memory, a magnetic disk or an optical disk.
The power supply component 1206 provides power for different
components of the electronic device 1200. The power supply
component 1206 may include a power management system, one or more
power sources, and other components associated with generating,
managing and distributing power for the electronic device 1200.
The multimedia component 1208 may include a screen for providing an
output interface between the electronic device 1200 and a user. In
some examples, the screen may include a Liquid Crystal Display
(LCD) and/or a Touch Panel (TP). When the screen includes a touch
panel, the screen may be implemented as a touch screen to receive
input information from a user. The touch panel may include one or
more touch sensors to sense touch, slide and gestures on the touch
panel. The touch sensor may not only sense the boundary of a touch
or slide motion but also detect duration and pressure related to
the touch or slide operation.
The audio component 1210 is configured to output and/or input an
audio signal. For example, the audio component 1210 may include a
microphone (MIC). When the electronic device 1200 is in an
operating mode, such as a call mode, a recording mode and a speech
recognition mode, the microphone is configured to receive an
external audio signal. The received audio signal may be further
stored in the memory 1204 or transmitted via the communication
component 1216.
The I/O interface 1212 provides an interface between the processing
component 1202 and a peripheral interface module. The peripheral
interface module may be a keyboard, a click wheel, a button and the
like. Such buttons may include but not limited to: a home button, a
volume button, a start button and a lock button.
The sensor component 1214 may include one or more sensors for
providing state assessments in different aspects for the electronic
device 1200. For example, the sensor component 1214 may detect the
on/off state of the electronic device 1200, and relative locations
of components, such as a display and a small keyboard of the
electronic device 1200. The sensor component 1214 may also detect a
position change of the electronic device 1200 or a component of the
electronic device 1200, the presence or absence of contact of a
user with the electronic device 1200, an orientation or
acceleration/deceleration of the electronic device 1200 and a
temperature change of the electronic device 1200. The sensor
component 1214 may include a proximity sensor configured to detect
a nearby object without any physical contact. The sensor component
1214 may also include an optical sensor, such as a CMOS or CCD
image sensor for being used in imaging application. In some
examples, the sensor component 1214 may also include an
acceleration sensor, a gyroscope sensor, a magnetic sensor, a
pressure sensor, or a temperature sensor.
The communication component 1216 is configured to facilitate wired
or wireless communication between the electronic device 1200 and
other devices. The electronic device 1200 may access a wireless
network based on a communication standard, such as WIFI, 2G or 3G,
or a combination thereof. In an example, the communication
component 1216 receives a broadcast signal or broadcast related
information from an external broadcast management system via a
broadcast channel. In an example, the communication component 1216
may also include a Near Field Communication (NFC) module to
facilitate short-range communications. For example, the NFC module
may be implemented based on Radio Frequency Identification (RFID)
technology, Infrared Data Association (IrDA) technology, Ultra-Wide
Band (UWB) technology, Bluetooth (BT) technology and other
technology.
In an example, the electronic device 1200 may be implemented by one
or more of an Application Specific Integrated Circuit (ASIC), a
Digital Signal Processor (DSP), a Digital Signal Processor (DSPD),
a Programmable Logic Device (PLD), a Field Programmable Gate Array
(FPGA), a controller, a microcontroller, a microprocessor or other
electronic components, so as to perform the above method.
In an example, the present disclosure further provides a
non-transitory machine-readable storage medium storing machine
executable instructions, such as memory 1204 to store instructions.
The instructions may be executed by processor 1220 in the
electronic device 1200 to implement the above methods as shown in
FIGS. 1-5. In an example, the non-transitory machine-readable
storage medium includes ROM, RAM, CD-ROM, magnetic tape, soft disk
and optical data storage.
The present disclosure may include dedicated hardware
implementations such as application specific integrated circuits,
programmable logic arrays and other hardware devices. The hardware
implementations can be constructed to implement one or more of the
methods described herein. Applications that may include the
apparatus and systems of various examples can broadly include a
variety of electronic and computing systems. One or more examples
described herein may implement functions using two or more specific
interconnected hardware modules or devices with related control and
data signals that can be communicated between and through the
modules, or as portions of an application-specific integrated
circuit. Accordingly, the computing system disclosed may encompass
software, firmware, and hardware implementations. The terms
"module," "sub-module," "circuit," "sub-circuit," "circuitry,"
"sub-circuitry," "unit," or "sub-unit" may include memory (shared,
dedicated, or group) that stores code or instructions that can be
executed by one or more processors. The module refers herein may
include one or more circuit with or without stored code or
instructions. The module or circuit may include one or more
components that are connected.
After considering the description and practicing the present
disclosure, those skilled in the prior art may easily conceive of
other implementations of the present disclosure. The present
disclosure is intended to encompass any variations, uses and
adaptive changes of the present disclosure. These variations, uses
and adaptive changes follow the general principle of the present
disclosure and include common knowledge or conventional technical
means in the prior art not disclosed in the present disclosure. The
description and examples herein are intended to be illustrative
only and the real scope and spirit of the present disclosure are
indicated by the claims of the present disclosure.
It shall be appreciated that the present disclosure is not limited
to the precise structures described above and shown in the
accompanying drawings and may be modified or changed without
departing from the scope of the present disclosure.
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